Konica-Minolta Bizhub C350 - Strange printouts ...

[com_flyer]

Hello my friends

I have a problem with my old but perfectly working (till now ...) Konica-Minolta Bizhub C350: all of a sudden, it shows strange bubbles and shifts on black prints.

In appendix, you will find a solid pattern test copy 100 in black (A3 format). The problem appears only on black prints. All other colors are OK.

Could it be the toner (original Konica, but the copier shows it will run out soon)? Or is it the imaging unit (used about 1/4 of its normal capacity). Since the problem doesn't appear on color prints, I think we can exclude the rest of the machine (transport section, transfer belt, transfer roller, fuser, etc.).

Thanks in advance for your help ...

Pierre
konica@ga21040816040_1.jpg

[copiray]

developer life?
try cleaning the charging crown

[com_flyer]

Thanks for your help.

I have (1) cleaned the charging corona, (2) changed the toner, (3) replaced the imaging unit, (4) cleaned the inside of the machine, (5) cleaned the syncronizing roller and clutch. Nothing helps; what looks like shifts or drops on the black test copies remains there ...

Could it be some electrical problem with the black unit? I am not a tech and don't know what kind of image an electric failure could produce.

Kind regards